[RegisterConfiguration] Streamline access to arch defaults, simplify Registers.

src/x87/assembler-x87.h

Index: src/x87/assembler-x87.h
diff --git a/src/x87/assembler-x87.h b/src/x87/assembler-x87.h
index fce1ab509032550059820a79e8ec399af1c2c67a..d4cde52ff6871c6bab09570a298f685b3887ee19 100644
--- a/src/x87/assembler-x87.h
+++ b/src/x87/assembler-x87.h
@@ -122,9 +122,6 @@ struct Register {
     Register r = {code};
     return r;
   }
-  const char* ToString();
-  bool IsAllocatable(RegisterConfiguration::CompilerSelector compiler =
-                         RegisterConfiguration::CRANKSHAFT) const;
   bool is_valid() const { return 0 <= reg_code && reg_code < kNumRegisters; }
   bool is(Register reg) const { return reg_code == reg.reg_code; }
   int code() const {
@@ -167,8 +164,6 @@ struct X87Register {
     return result;
   }
 
-  bool IsAllocatable(RegisterConfiguration::CompilerSelector compiler =
-                         RegisterConfiguration::CRANKSHAFT) const;
   bool is_valid() const { return 0 <= reg_code && reg_code < kMaxNumRegisters; }
 
   int code() const {
@@ -178,8 +173,6 @@ struct X87Register {
 
   bool is(X87Register reg) const { return reg_code == reg.reg_code; }
 
-  const char* ToString();
-
   int reg_code;
 };